1. Field of the Invention
The present invention relates generally to an image forming apparatus. More particularly, the present invention relates to an image forming apparatus of the type having ink jet heads used therefor to print a cloth used as a printing medium with ink by ejecting ink toward the cloth.
2. Description of the Related Art
With respect to a conventional image forming apparatus as disclosed in Japanese Patent Application Laying-Open No. 34461/1981, one set of ink storing tanks and one set of ink feeding passages are arranged for one set of heads of which colors are represented by yellow (Y), magenta (M), cyan (C) and black (Bk).
On the other hand, a textile printing apparatus of the type having an ink jet system employed therefor is a technology which is increasingly known in the art in recent years. This type of textile printing apparatus has advantages that an image capable of being printed on a cloth has a high degree of freedom and a whole textile printing operation can be achieved at a reduced cost for the main reason that no original plate is required for an image to be printed on a cloth in contrast with a screen printing technology. The conventional textile printing apparatus having an ink jet system employed therefor is exemplified in Japanese Patent Application Laying-Open No. 212851/1993 but any particular description on a feeding system for an ink jet head is not seen in the foregoing official gazette.
However, in the case that the conventional ink jet printing apparatus is used as a textile printing apparatus as it is, there arises a problem as noted below. Specifically, the textile printing apparatus has a necessity for printing several kinds of clothes such as cotton, silk, polyester or the like with a same liquid of ink. It is desirable from the viewpoint of a quality of printed image on the cloth that the kind of ink is changed to other one in consideration of adaptability of the cloth to the ink. In addition, to make it possible to print the cloth with ink having a metallic color, a clear red, a clear blue or the like each of which has a difficulty in visual expression with ordinary colors of Y, M, C and Bk, it is necessary that the present kind of ink is changed to ink having a special color. To this end, when the kind of ink is changed to other one, it is necessary that ink remaining in the ink feeding system is discharged from the latter, thereafter, it is cleaned or washed, and subsequently, it is charged with a new kind of ink. However, a series of operations as mentioned above are very troublesome and time-consuming. Further, in the case that ink jet heads are detachably attached to the opponent members to make it easy to exchange the present kind of ink jet heads to other ones, the opponent members should also be cleaned or washed.